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T O P I C R E V I E W

Aeropix

There is a discussion within NASA regarding possible abandonment of the ISS until such a time as further Soyuz launches can be deemed "safe".

Latest schedule I heard was that the six astronauts currently manning the ISS would be brought home on the two Soyuz craft currently docked at the ISS, leaving the ISS unmanned after November, until the Progress crash investigation can be completed.

Do you think the abandonment of ISS is really based on technical fear, or perhaps at least partially politically motivated, given America's lack of space transportation capability?

I'm wondering what other options exist to avoid this circumstance. Seems like redeploying Shuttle is off the table, as is utilizing Chinese rockets for transportation. How about SpaceX, how close are they to having the Dragon "man-rated"? Other commercial operations?

garymilgrom

This is entirely a technical concern due to two Soviet rockets failing in successive launches. I believe Dragon is one successful flight away from qualifying to carry cargo to the ISS, not sure about manned flights.

issman1

For NASA to even contemplate abandoning the ISS confirms my worst suspicions about the risk-averse nature of today's space bureaucracy.

It's a far cry from the famous clarion call that failure is not an option. Some may lament the demise of American supremacy in human spaceflight, but it's so much more than that.

The US chose to lead this programme, and invite the various participating countries, and should have anticipated all permutations and scenarios of the risk to ISS. In its current, final configuration the danger of losing something unique, valued at tens of billions and huge in size does not justify nor warrant abandonment.

The Soyuz TMA-02M lifeboat will be nearing its expiration date before the end of the year, so either fly up a replacement vehicle remotely or with a fresh crew. If asked, Fossum-Volkov-Furukawa would doubtless stay on board several additional months (they are professionals after all). Or is there another pressing reason to leave ISS empty and at the mercy of a major systems malfunction?

Robert Pearlman

Roscosmos has identified the cause of the Soyuz-U upper stage failure and so the expectation is that Soyuz TMA-22 will launch with three crew members for the space station in early November, making this discussion somewhat moot, but...

quote:Originally posted by Aeropix:Do you think the abandonment of ISS is really based on technical fear, or perhaps at least partially politically motivated, given America's lack of space transportation capability?

It is neither of these reasons.

NASA addressed the possibility of de-manning (not abandoning, as the station would still be under full control of the ground) as a result of Soyuz landing constraints.

Prior to the loss of the Progress, the Soyuz TMA-02M crew were scheduled to return to Earth on Nov. 17. Delaying their return (beyond the few days under consideration now) would see them landing in the dark, which violates Soyuz landing criteria. Further, they would be landing in severe winter weather conditions in Kazakhstan, making their recovery much more difficult.

So were the station de-manned, it would only be in response to ensuring the crew safely lands and can be recovered in quick order.

But as noted, Soyuz TMA-22 is now tentatively targeted for a Nov. 2 launch, so barring any unforeseen issues, the station will remain continuously manned.

Blackarrow

Does this not beg the question: how serious a problem would there have to be on board the ISS to justify an emergency departure in mid-winter? Put it another way: is there a level of emergency which would result in an emergency departure in summer but would be tolerated in mid-winter?

Robert Pearlman

Crew safety is considered paramount.

If, in an emergency, the order is given for the crew to evacuate the station and return to Earth, then it because their lives are at more risk staying in space than they are remaining on-orbit.

Soyuz crews receive survival training, including surviving winter weather conditions, but if such can be avoided (as in this case), then the program strives to do so.

Spacepsycho

What is the rush to evacuate the ISS by a certain date? Aren't there contingencies and consumables for the crew to extend their mission? Can't the crew inhabit the station for an extra month or is there a medical issue that mandates the crew must be returned to earth by a certain amount of time?

Blackarrow

quote:Originally posted by Robert Pearlman:If, in an emergency, the order is given for the crew to evacuate the station and return to Earth, then it is because their lives are at more risk staying in space than they are remaining on-orbit.

This is precisely my point. Now that the upward and downward transport of American astronauts is reliant on Russian spacecraft, there might come a time when something happens which causes ISS Control to weigh up the issues affecting crew safety, and the decision whether to stay in space or return to Earth might be decided (on a narrow balance of risks) by the undesirability of bringing a crew down in severe central Asian winter conditions. Given precisely the same circumstances on board ISS in the northern hemisphere summer, a different decision might be made.

The sooner America can launch and retrieve her own astronauts again, the sooner astronaut safety will not be dependent, even to a small degree, on the climate in central Asia.

Rusty B

quote:Originally posted by Spacepsycho:What is the rush to evacuate the ISS by a certain date?

The Soyuz only have a certain lifetime in orbit. The crew has to use them to return while they are still safe. If another Soyuz has not been launched in the meantime to replace it, there is nothing that can be done.

Robert Pearlman

To expand on what Rusty wrote, all spacecraft have a certified lifetime on-orbit, after which the risk of critical system failures increases. For the space shuttle, it was about three weeks. For the Soyuz, it is 200 days.

By Nov. 17, Soyuz TMA-02M will have been in space for 164 days. It is certified to stay 36 more days in space, but as mentioned, it would then be landing in the dark in winter.

Robert Pearlman

quote:Originally posted by Blackarrow:Now that the upward and downward transport of American astronauts is reliant on Russian spacecraft...

Since day one of Expedition 1, Soyuz has always been the lifeboat for the International Space Station. The space shuttle was never an emergency response craft for evacuating the station crew. If evacuation is ever required, it will for reasons where action is needed before another spacecraft (of any type) can launch.

That is why crew members go through survival training, for the unlikely situation when staying on-orbit — either on the station or aboard the Soyuz until whatever the problem is with the station is addressed — is no longer a safe option.

Adding U.S. commercial craft to the station may expand return options, but those craft will have their own landing criteria as well. Depending on the design, weather, wind and daylight may all be factors.

Blackarrow

Point taken, but my point remains valid: the sooner America (whether NASA or SpaceX or others) is once again able to launch and retrieve astronauts, the greater the options in any given "off-nominal" scenario.

Robert Pearlman

Roscosmos today scheduled the launch of Soyuz TMA-22 for Nov. 12. The Soyuz TMA-02M crew is currently set to return home on Nov. 17.

issman1

While I hope the Soyuz TMA-22 launch date is met, what happens to ISS staffing if it slips till after the scheduled departure date of Soyuz TMA-02M?

A Soyuz capsule would still "be landing in the dark in winter" even if there was an emergency evacuation of the ISS in December, January or February.

Robert Pearlman

The Soyuz is capable of landing in the dark (it has before) and even in winter weather conditions, it is just not preferable that it does so as it makes recovery operations more difficult.

Robert Pearlman

quote:Originally posted by Robert Pearlman:Roscosmos today scheduled the launch of Soyuz TMA-22 for Nov. 12.

NASA and its international partners (including Roscosmos) have agreed to a tentative schedule that has Soyuz TMA-22 launch on Nov. 14. Soyuz TMA-02M will return to earth on Nov. 22. Soyuz TMA-03M will launch on or about Dec. 26.